Configuration for BLTouch

Weevil

I have the Duet 3. For some reason, the configurator will not let me set up the BLTouch, As I understand it, only the pins for IO_7 can be used for the BLTouch for Duet 3. In the Z-Probe section, I can set the Input pin and Modulation pin but not the PWM Control Panel (BLTouch Only). If I set the PWM control I cannot select Input pin and Modulation pin. On top of that, any variation results in the Configurator assuming I do not have a Z-probe at all.

Please help. A sample g-code would be extra helpful. Thanks.

droftarts

@Weevil You don't need to set a modulation pin, that's for probes that need modulation, which the BLTouch does not, so leave it unassigned. Perhaps the config tool could be clearer on this. You only need to set the 'Input Pin' and 'PWM Control Channel (BLTouch only)', then select 'BLTouch' in Endstops > Z Probe > Z Probe Type. Doing this generates this:

; Z-Probe
M950 S0 C"io7.out"                           ; create servo pin 0 for BLTouch
M558 P9 C"io7.in" H5 F120 T6000              ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X0 Y0 Z2.5                          ; set Z probe trigger value, offset and trigger height

As others have suggested in other threads, change G31 P500 to G31 P25 to improve sensitivity.

You can connect a BLTouch to any pin I think, but as it says in the first point here,

On Duet 3 it is one of io4.out, io5.out or io7.out. If you use one of these pin names, you will not need to invert the output.

For wiring, see https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Duet_Num_3
For more details on setting up BLTouch with RRF3, see https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Software_setup_RepRapFirmware_Num_3

Ian

Danal

This works for me on a Duet 3:

M558 K0 P9 C"^io4.in" H5 A5 T6000 S0.02   ; Z probe BLtouch - Set the height of the bed when homing G28.  Combined with content of bed.g as invoked by G32, levels bed. Also used for Mesh.  
		                          ; Hn = dive height
				          ;   A bigger dive height prevents a situation where the bed is out of alignment by more than the dive height
                                          ;   on any corner, which can crash the hot-end into the bed while moving the head in XY.
                                          ;   Probing speed and travel speed are similarly reduced in case the Z probe isn't connected properly (or
                                          ;   disconnects later after moving to a point) giving the user more time to stop.
                                          ; An = Number of times to probe each point. 
                                          ; Tnnn = Travel speed between probe points. 
                                          ; Snnn = Tolerance when probing multiple times. Two readings inside this window and we move on. 
M950 S0 C"^io4.out"                       ; Servo Control Pin for BLtouch.

Weevil

@Danal Ok, I tried your setting. The probe now lights up but it does not deploy or retract.

droftarts

@Weevil read this? https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Commissioning_Testing

Ian

Weevil

@droftarts The test did not work. Upon powering up the board, the BLTouch deploys and retracts several times which I assume is a self-test. However, I cannot get it to deploy or retract. I am using this code:

M950 S0 C"io7.out"
M558 P9 C"io7.in" H5 F120 T6000
G31 P500 X0 Y0 Z2.5

droftarts

@Weevil that means it’s getting power. Check continuity on your wiring, and that its connected to the correct pins. Maybe post a picture. What M280 command are you sending to test? If the BLTouch was not setup correctly in the config tool when you downloaded config and other files, the deploy and retract macros will be incorrect.

Ian

DIY-O-Sphere

@Weevil

https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Commissioning_Testing

That are the old codes for RRF2

You have to replace P3 by P0 and omit I1
So for RRF3 the codes are
M280 P0 S10
M280 P0 S90

Edit:
Or instead you can use M401 and M402 (for Typ P9 in M558)

Weevil

@DIY-O-Sphere Thanks, the tests confirm the BLTouch can deploy and retract on command. However, when I launch deployprobe.g from the web interface nothing happens yet the code matches:

; deployprobe.g
; called to deploy a physical Z probe
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Sat Feb 22 2020 12:08:41 GMT-0800 (Pacific Standard Time)
M280 P0 S10 ; deploy BLTouch

The same issue happens with retractprobe.g

Perhaps I am over thinking it as the code clearly works if I enter it as a single line command.

Danal

The macros have no upper case letters, and are in the /sys directory? (Not in the macro part of DWC... just files in 'system').

droftarts

@DIY-O-Sphere said in Configuration for BLTouch:

@Weevil
https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Commissioning_Testing

That are the old codes for RRF2

You have to replace P3 by P0 and omit I1

Good point, I’ll update the docs.

Ian

Danal

@droftarts said in Configuration for BLTouch:

Good point, I’ll update the docs.

Already done.